Method of making radiator cores



Patented Oct. 26, 1926.

STATES 'PATENT Y@lriFla FRED M. OPTZ, OF MILWAUKEE, WSCONSIN, ASSIGNOR T0 OPITZ MANUFACTURING COMPANY, OF MIL'WA'KEE, WISCONSN, A COROR-ATION OF'WISCONSIN.

METHOD OF MAKING RADIATOR CORES.

Application filed November 9, 1922.

My invention relates to automobile radiators and the lilre, and more particularly it relates to the method or process of manipulating the sheet metal of which 4the radiator `(fore is constructed, and the structure resulting therefrom.

The radiator made by my `present inrention is covered by my prior Patent No. l,- lOeHlGO of January 17, 1922,-upon which the present inv-ention -is an improvement.

The present application covers certain n'iatter divided out `of the application for the above patent and certain new matter as will be apparent from inspection.

rl`he' fundamental idea involved in the present invention is toconvcrt a flat strip of sheet metal, preferably brass, copper or bronze, into a suitably formed half tubefof the type disclosed in my prior patent, with a minin'iun'i of operation, and with a mininuun of punishment or working of the metal.

l have devised a way of doing this by Certain steps which will be disclosed in detail and claimed herein, and have devised means for performing the steps, which means is disclosed :in detail and claimed in in v copending application, Serial No. G38,- (398, tiled May 14, 1923.

The finished radiator is made up of strips or sheets all of which are active, ythat is, torni a wall between the water to be cooled and the air outside. These strips or sheets have integral loops along their edges, frontand rear. the purpose of which loops is first to space the sheets properly and to Vhold them together in proper relation, second to aid'in the dissipation of heat, and third,to forni an ornamental and protective front lfor the .water tubes.

The water tubes Vhave integral lateral wines or aocliets which are `formed in register with these loops aforementioned. ihese wings or pockets which may-terni water legs provide additional surface for water cooling and they also aid in breaking up the air streams and give an improved appearance to the radiator, all as explained in'my priorpatent above referred to.

There Vis a peculiar relation between the marginal loops andthe lateral-wings or projections on the tube. The flat strip or sheet from which each side of a `tube is formed is of very thin stock. It should notbe stretched to any appreciable.degree and in constructing the radiator of myy invern-trionfi. :li-aire Seral No. 599,792.

related the loops and the lateral wings or projections that the same amount of metal in linear length is taken up by each, that is, the -loops and the projections. At the same time, provision must be made for depressing' the central longitudinal part of the strip to form a trough. This trough forms one-half of the tube.

According to the preferred procedure, I first corrugate or form ridges inthe sheet transversely preferably in the exact form of the finished loops. Yl`his may of course be varied, but l find it to be highly advantageous in order to set originally and thereafter to preserve the correct pitch of the ornamental loops and of the water legs or lateral projections.

After the initial corrugating or ridging which may be done by corrugating rolls as I shall elsewhere explain, the corruga-l tions are slit in a direction longitudinal with respect to the strip and transverse with respect to the ridges, along the margins to delimit or demarcate the loops from the body of the tube. This operation is Apreferably performed in a punch press by means of suitable dies.

The third stage is to depress the central longitudinal part of the strip to form a gutter or trough for the tube half. This third stage is preferably performed simultaneously with a 'fourth stage or operation, namely, the pinching together of the corrugations or transverse ridges between the slit marginal portions which forni the loops. There is a peculiar relation between the formation of the gutter or trough and the pinching of the corrugations to form the lateral wings or water legs of the inished tube. As the central longitudinal part is depressed the'outer ends of the transverse ridges or corrugations are pinched together to a greater extent than are the inner or central parts which oiierlie the bottom of the. gutter or groove. It is a well known fact that a transverse rib or corrugation of sheet metal cannot well be bent across the corrugat-ion without distortion of the corrugation or stretching of the metal. I have avoided the difficulty by pinching the met-al togetherat the .edges and thereto determining the lline of the. transverse bend where the pinching together begins. This pinchingtogether is graduated vfrom the outer edges lof vthe corrugation to the line of the bend ofthe corrugation.

The above named operations of pinching the slit edges of the corrugations and forining the bend may be performed in a punch press by suitable dies.

'The final and eXact shaping of the lateral tioned may be made in a` progressive die all on the same machine as will be more fully described in my copending application above referred to.

In order to acquaint those skilled in the art with the manner of constructing the radiator of my invention according to the precent novel method. I shall now' describe with the aid of the accompanying drawings the preferred manner of carrying my invention into effect.

In the accompanying drawings:

Figure 1 is a perspective view of a flat strip of metal from which the tube half is formed;

F 2 is a perspective view of the strip or sheet after the initial corrugating or ridging steps;

F ig. 3 is a plan view of the corrugated strip after the second or slitting operation;

Fig. l is a transverse longitudinal section of the corrugated strip taken on line l--d of Fig. 3;

F 5 is a` transverse section taken on line 5 of Fig.

Fig. 6 is a plan view of the strip after 'the next stage of operations which includes the step otl pinching the intermediate parts of the corrugations or ridges and simultaneously pressing out the central longitudinal por-- tion of the strip to form a gutter or channel;

Fig. 7 is a longitudinal sectional view taken on the line 7 7 of Fig. 6 across 'the wings or -water legs;

Fig. 8 is a similar view taken on line of F 6 across the pinched ends; Fig. 9 is a. transverse section taken on line 5)-9 of Fig. 6 through one of the wings or water legs and the adjacent marginal loops;

F ig. l() is a plan view of the strip or tube half in the next stage of progression, the lateral wings or water legs'are brought more nearly to form, that is, slightly more coinprcesed and the outer edges brought closer er. in fact, into contact;

p s. 11 and 12 are sections taken on corresponding lines as indicated on Fig. 10;

Fig. 112A is a tra .sverse sectional view of one of the lateral channels in my novel half tube construction illustrating one of the steps inolved in the forming of same;

Fig. 18 is a plan view of the final stage of the ube half, the joining margins just inside the loops being liattened down into a common plane, the tops `of the water legs or lateral projections beingsquared up, the ends thereof pinched closely into contact and `the metal between the water legs being flat- Fig. 18 is a face view or front elevation ot a portion of the assembled core;

Fig. 19 is a sectional view illustrating the cross section of the semi-hexagonal corrugation employed in the marOinal loops of my construction;

Fig. 20 is a sectional view illustrating how the ends of the channel projections are pinched together; and

Fig. 21 is a more or less diagrammatic view illustrating the cross-section of a channel in my construction.

Whereas, in the accompanying drawings the corners where the sheet is bent are shown as being sharp, it is to be understood that I avoid as much as possible all sharp corners and even if the inner side of a bent portion of the sheet 'is sharp it will be understood that the outer surface thereof does not assume an absolutely sharp corner. Similarly, where the metal is folded to gether; it will be understood that absolute meeting of the edges is not essential since all edges are dipped in solder which joins and seals these edges.

lVhereas. I shall describe herein the pre ferred method of procedure in making up the radiator core of my invention, it is to be understood that the order of .steps which I shall describe may be considerably varied. In fact, I have constructed the radiator of my invention according to the steps here- 'in described but varied considerably as to the order in which they are accomplished.

I employ as suitable stock or metal a strip 1 of brass. bronze, or copper; which is formed into a continuous gutter or channel with `joining` margins and ornamental and spacing loops at the edges which is cut into suitable lengths and these lengths are placed face to face to form a tube. According to the preferred mode of procedure; I bend up corrugations 2 from the plane of the strip 1. These corrugations are preferably semi-hexagonal in shape with fiat tops and flat sides, but can be any other shape, the various angles of bending being substan` tially 600; the tops. bottoms and sidesI of the corrugations being all of substantially equal length. It is well known that the sides of an inscribed regular hexagon are equal to the radius of the circumscribing circle. Hence, each of the fiat sides of a corrugation are equal to half the distance across the base of the corrugation which base corresponds vto the .diameter of the circumscribing circle. I. shall designate the portion of the .sheet lying between corrugations by the letter A and the three sides ot the corrugations, respectively, B, C, and D.

This matter oit corrugating thel strip l may be performed in corrugating roll-s as l shall describe elsewhere.

netter the strip has passed through the corrugating; rolls it is then slitted asindicated in Fig'. 3 by slits 3 and l adjacent the edges, these slit-s extending across the walls lb, C, and D oit the corrugations 2 near the margins ot the sheet. Thus, the ornamental loops 5 and t5 are cut from the .sheet and being; already formed to the right pitch, they are not thereafter altered.

The slittingl ot the corrugations atI 3 and l is preterably performed upon a punch press with suitable dies. ln order to malte the .slits 3 and l it is necessary that the metal be sheared. ott, and to do this, the edges ot the metal just inside the loops 5 and 6 is depressed as indicated in 3 andy The middle part ot the transverse corrugations 2 still retain the shape ot the original corrugations and ot the loops 5 and 6. lt is to be understood that the slit-ting operation may precede the corrugating or 'folding operation it desired. However, l tindl` it more desirable to slit the corrugations after they are formed than to slit the sheets before the corrugations are formed, since this mode ot procedure permits the loopsto `be formed integral with the main body ot the sheet and hence to be brought to exact torni without any interference with the .slitting operation, and such distortion that occurs from the slitting); operation does not atl'ect the accuracy ol" the il'oldingr or corrugations. lt is to be understood turthermore that the slitting` operation may be performed simultaneously with the corrugating operation it desired.

rllhe nent stage ot operation according); to the preferred mode ot lnocedureis to form the channel by olsettinn the central longitudinal part. ot the sheet with respect to the margins, which nn'zrgins remain'relatively in the same position as the original sheet l bctore the corrugations 2 are raised therefrom.

ln the present specification and in the claims l. employ the term CGthe orinjinal plane ot the sheet to designate a certain reference plane* which corresponds in 2 to the plane ot orieinal sheet l and also the plane ot the es n. liietween corrugations 2. 'llhese 'laces which l may term the bottoms ot the corrugat'ions still lie in the plane ot; the

original sheet in the stage represented by' Figs, 3 to 5.

The next step or stage et operations involvesltwo actions. @ne isthe fundamental action of forming a channel or trough longitudinallv of the sheet b f offsetting" the cen- .y l is tral part ot the sheet loneitudinallv into aV A* vb Y .l

plane parallel with the originalplaneot tne- 'llhis forming; ot. a gutter: or. channel.

sheet. is necessary` in. order.' to form. the: ultimate ffl tube as the thicknessot the tube when linished is equal to twice the amount ot otlset ot the bottom ot the channel. ln pertorming` this operation ot oiiisetting the bottom ot the channel with respect to the original plane oi the sheet, it is necessary to observe the requirement ior a sealing inerqin each edge just inside ot the ornan xntal loops. Also, in this operation et forming the rut tor or channel, it is i'iecessary to bend the metal ot the sheet across the cor` u; "lona Also, since these corrugations hetnet. the slit ends which detine the loops are to be `termed into closed pockets or water legs, it will be necessary to seal or close these slit ends. This combined action ot' torming` the channel or gutter, bendingl across the c rugations andsealine the ends ot the corrugations, lV perform by a relatively simple but eliective operation follows:

l arrange to close the ends ot tv gations by pinchiingl together the ni, A ot the corrugation at each end whe slit tree ot the loops. New, since this pinchl ing together will result in a told or seam which preterably lies in a plane at right angles to the original plane ot' the sheet and transverse to the longitudinal axis ot the sheet, and since these pinched together walls are a continuation, or, in tact, merely the outer ends ol the side vra ot" the transverse corrugations between. the loops, l term them oorrugations so that they will be ot l thickness than the tace G ot the original corrugation, and will have vertical side wall* parallel to each other and parazi plane ol the pinched toeether ma. plane ot' the seam where the pinched gether ends enga e each other, lies substantially centrally ot the original` corrugations 2 and centrally ot the squeezed together cor rugat-ions which begin to assume thel term ot pockets. At the same time that the ends are pinched together and the side walls are squeezed towards each other, the bottom ot the channel is depressed so as t torni the gutter and sealing margin.

Referring now more particularly to Figs. G to 9, inclusii'e, which show the sheet atte-r this compound operation oi" depressing th bottom ot' the gutter, squeezL-ing ner the top of the intermediate part ot the corrugations and pinching` towards each other the walls at the ends thereof, .it will be se n that theV original loops .5 d G are not d turbed. Also, the bottoms it are still of the original width completely across the sheet. However, these bottoms iii have now been dividedinto tire separate parte, namely, the middle orl bottom part l0, two sloping laces 11 and 1Q. which form the ends et' the tT inthe finished tornnront and rear, and outer faces 13 and le.

The parts 13 and 141 ot original tace: or bot-toni.. At. comprise in reality twoparte,

namely, an outer part, the width ot the loops and an inner part which is a part of the sealing margins, which extends from the inner edge ot' the loops to the bend formed between the parts 11 and 13. By the initial eorrugation illustrated in Fig. 2, the original sheet 1 was diminished in length by onequarter, in other words, by the width oi? one of the faces A, B, C or D. Since tace A remains unchanged in width and therefore occupies one-third ot the corrugated sheet, the other two-thirds of the length ol the corrugated sheet is the space occupied between points and 18 as viewed on Figs. 4 and 19. In other words, assuming that the semi-heiragon is circumscribed by a semicircle, the side A is of a width substantially equal to the radius ot' the circumscribing semi-circle, while the space occupied by the corrugation is equal to the diameter of the circuinscribing semi-circle. rihe corrugations have been reduced in width as shown in Figs. (i to 9, inclusive, by the action et dies which squeeze the top parts et these corrugations together into a narrow transverse projection or wing having substantially vertical walls as is apparent from Fig. 7. These vertical walls 21 and 22 are ot a width, that is, a vertical width, as viewed in Fig. 7, substantially equal to one-half the radius of the circumscribing circle above re` erred to. These vertical walls 21 and 22 were formerly part of the side walls C and D et the corrugations 2, the rest ot the side walls of the corrugations now appearing in slanting walls 24 and 25 which go to define parts of the end and bottom walls ot the gutter. gral with the walls 21 and 22 at the ends et the pockets 20, where these walls 21 and 22 are pinched together substantially in contact as will be apparent from Fig. 8. In the process of thrusting out or oilsetting the bottom of the gutter, it was necessary to make tour bends, namely, th-e bends indicated at 27, 28, 29 and 30, as viewed in Fig.

(lll

9. In forming these bends, the pinching together of the ends of the pockets 202O assisted materially in deining the region where the corrugations would be bent. That is to say, the ends ot the pockets where they are pinched together are triangular. lVhere the base of the triangle joins the full width of the pocket 2O there is a gentle bend as indicated at 31 and 32 in Fig. 9. There is no bend which corresponds exactly or noticeably with the bend along the lines 27 and 30, since the triangular Iend parts of the pockets taper downwardly on substantially a straight line. rllhere is, I believe, a very slight stretching of the sheet metal where the base of the triangular end part joins the rectangular middle part oic these sockets since I find that these pinched together ends extend slightly under the loops 5 and 6 as indi- The vertical walls 21 and 22 are inte-A cated in Fig. 9. It will be noted particularly in Figs. .7 and 9 that the tops of the pochets 20 now lie above the tops ot' the loops o and 6, the vertical walls 21 and 22 which are olf the same height as the vertical walls 21 and 22 and, in fact, are merely continua tions of the same, are ot the same height, namely, one-halt ot' the radius ol the inscribing circle. It is necessary in order to finish the pockets to close together tightly there walls 21 and 22, or at least tight enough so that they will be closed by solder.

The next stage or step which is illustrated in Figs. 10, 11 and 12, comprises merely a squeezing together ot the pockets 2O along the sides 21 and 22 and a squeezing together oit the end portions 21 and 22 thereof. These walls are brought substantially inte contact so that the final stage of squaring up will bring these walls 21 and 22 substantially into contact. In the stage illustrated in Fig. 10, the side walls 21 and 22 of the cerrugations 2O are brought slightly closer together' with a result-ing bulge upwardly ol the upper wall 23. The walls 21 and 22 are not vertical'at this stage, but are closer together at the top than at the bottom so that in the final 'forming operation illustrated in Figs. 13 to 17, inclusive, the bringing down into the horizontal of the walls 24 and 25 will throw inward slightly the lower ends ot the walls 21 and 22 and bring them into parallelism substantially normal to the original plane of the sheet. In the same manner the bringing down of the walls 24 an-d 25 which are really continuations ot the walls 24 and 25 will serve to close together the walls 21 and 22 of the ends ot these pockets. Fig. 12A illustrates the above condition.

In the linal stage or step, the pockets 2O are squared up, the top walls ot the corrugations are pressed flat into a plane suhstantially the same as the plane ot tl e tcps of the loops 5 and 6 and the walls 24 and 25 and 24 and 25 are all brought down into the plane ot the adjacent part, so that the flat wall 31 forms the bottom, this entire length occupying substantially vtive-sevenths of the length of the tube and the corrugations occupying substantially only two-sev enths of the length of the tube. rEhe gutter which terms the hal'ot the tube is now well defined, the margins 32 and 33 appear plainly and they lie in the same plane as the original plane oi' the sheet. The end walls 11 and 12 are also clearly deiined. A portion oi the sealing margin is formed of the walls 24 and 25 which have been brought into the same plane as the original bottoms et the corrugations. rEhe pinched together ends 21 and 22 in the final finished stage, illus -trated in Figs. 13 to 17, inclusive, the length of the metal is distributed as follows:

Referring now to diagrams Figs. 19, 2O

lit)

and 2l, and assuming that the metal has no appreciable thickness, the various lengths are taken up as follows:

This assumption of .no thickness in the metal does not introduce vany material errors. The entire length of the sheet was taken up in the corrugating stage by lthe faces A, B, C and D of successive corrugations. As previously explained, this resulted in foreshortening the sheet one-fourth. The remaining three-fourths are distributed in three equal parts, namely, one part or onethird remains in the original face A ivlhich extends completely `across the finished ltube without alteration, the remaining threefourths of the original length are now disposed in tivo-thirds of the finished tube. In the loop, the disposition is as fol-lows:

Sides B, C and D of the finished loops are each of a length in the linear direction of the tube, the same as the length of the face A.. Since they 4are disposed as the three sides of a regular hexagon they occupy longitudinally only the diameter of the .circuinscribing circle, the radius of Which is equal to the length of the face A.

In the pinched together ends (see Fig. 20) the metal Which is shown in Fig. 9 in the faces B, C and D has now been disposed in faces E, F, G and H. The faces E and F are substantially the same length as the faces and D. While the su-m `of facesG land H is equal to C. In other Words, the faces G and H are merely face C folded into a lfiight. This bightl extends upwardly for a distance substantially equal to one-half the radius of the circumscribingcircle. At the central part Where the full Width of the pocket 9,0 is formed, the metal previously disposed in the faces B, C and .D lis now disposed in faces I, J, IS, L and M. Of these .tive faces, the sum of faces I, K and M is equal to the diameter of the circumscribng circle, in other Words, is equal to the .sum of faces B and D, While faces J and L together are equal to the vlength of face C, that is, the length of the radius of the circunr scribing circle. IIenee,the extentor height of the projection 2O upon the bottom of the gutter or channel is substantially one-half of the radius of the circumscribing circle and the depth of the gutter is slightly less than cne-half the radius of the circumscribing` circle.

After these tube halves kare properly formed, they are assembled as indicated in Fig. 1S, so that the loops are in register with each other and form `an ornamental front at back and rear With the Water legs substantially in contact. The group of assembled tubes is held in a .frame and the front and rear joining margins and loops are dipped in solder to a depth 'suflicient to seal the sealing margins and -to join together the vloops `at the vfront but ynot `deep enough to join together the Water legs. The resulting structure has remarkable resiliency and strength in addition to excellent effici ency. The tubes Will standrepeated freezing Without injury. The Water channels are large andstraight. The metal is used to a maximum advantage.

I d o not intend to be limited to the details above .shown and described, nor do I intend to limit my invention to the order of the Y steps above recited, except as the same is particularly stated in the appended claims. The longitudinal channeling may be formed ahead of or simultaneously With the cross corrugation instead of after the same, Which I have above described.

l. The herein described process for forming a radiator half tube out of a strip ef sheet metal comprising, corrugating said strip with equally pitched transverse ridges, slitting alternate ridges to free the central part of the transverse ridges from the marginal portions, moving the longitudinal central portion of the corrugated strip out of the prior plane thereof to form a gutter, and closing together the slitted ends of the transverse ridges.

2. The herein described method of forming a tube half from a strip of sheet metal which conjiprises, raising flat topped ridges or folds transversely on the strip, slitting the ridges adjacent the margins of the strip to form free loops and pinching together the ends of the ridges or folds Where they have been slitted free of the loops.

3. The herein described Aprocess of forming a. tube half from a strip of sheet metal Which comprises raising flat topped ridges or rfolds transversely of the strip, slitting the ridges adjacent the marginsoof the strip to for-m free loops along the margins, pinching together the slitted ends of the ridges or folds and raising the central longitudinal part of the strip to form a gutter.

il. The herein described process of formingva t-ube half from a strip ofsheet metal which comprises raising flat topped ridges or-folds transversely of the strip, slitting the ridges adjacent themargins of the strip to form free loops along the margins, pinching` together the slitted ends of the ridges or folds and raising the central `longitudinal part of the strip to form a gutter, and `forniing flat joining margins for the strip just insideof the line of slits along each margin of thestri-p.

5. In the herein described process of forming atube half 'from a strip of sheety metal., the process of forming ornamental connecting loops on the margins of the sheet which comprises, forming semi-hexagonal corrugations across'the Width of the strip or sheet, slitting the corrugations near the margin of thesheetto `detinegfree loops along the marlll) Btl

gin.` and pinching together the slit edges ot the corrugations to form closed pockets.

G. The herein described process comprising, torming llat sided semi-hexagonal corrugations transversely ot the sheet, slitting alternate ridges along three sides to torm tree seini-hexagonal loops, and squeezing togetherthe intermediate portion of said alternate ridges or corrugations to bring a portion ot' the metal into a common plane substantially parallel to but out of the plane of? the main iart ot the sheet, closing together the ends vot said ridges or corr-uga tions and forming joining margins inthe plane ot the main part ot the sheet.

7. rlie method ot 'forming Aa tube halt comprising, corrugating a sheet by repeated transverse bends at equally spaced points along the length ot the sheet as follows, at point l countercloekrvise 600, at point 2 clockwise GOO, at point 3 clockwise 600, at point Ll eountercloclmvise` GOO, and then repeating the above schedule along the length ot the sheet; slitting the corrugated strip trom points l to Ll: along both margins to form loops 'trom the outer ends of the cor` rugations; closing together the slit edges et the corrugations to form lateral pockets; and raising the longitudinal median part ot the strip to orm a gutter.

il. The method ot forming a tube halt' which comprises; corrugating a strip by a series ot t300 bends to raise a series ot' semihexagonal ridges trom the plane of the sheet or strip; slitting said ridges on lines parallel to and spaced trom the margins of the strip or sheet; raising the central longitudinal part of the sheet with the ridges thereon above the plane ot the sheet to torni an inverted gutter, squeezing towards each other the upper parts of 'the side Walls of the ridges; and pinching together the slit ends ot the ridges to close the pocket, and to term a dat continuous joining margin in the plane ot the sheet along the sides ot the sheet inside of the loops.

9. rShe method ot forming a tube halt ltrom a strip of sheet metal which comprises; eorrugating the strip to raise a. series ot semi-hexagonal transverse ridges tro-in the plane ot the strip; slitting said ridges to detine semi-hexagonal loops along both margins oit the strip; raising the central part of the sheetand the ridges to form a gutter; squeezing together the side Walls ot the ridges to reduce the thickness of the ridges; pinching together the slit ends of the ridges to torni closed pockets trom said ridges; pressing down the ridges't-o bring their tops into substantially the level of the top ot t-he loops, and pressing down into the plane ot the strip the metal adjacent the pinched ends to form a sealing 'flange at each margin within the loops.

10. The method of forming a tube halt which comprises; corrugating the strip to form flat sided and flat topped ridges above the plane ot the strip, said ridges having their tops lying in a plane parallel to the plane ot the strip; slitting said ridges to de line loops along both margins` of the strips; squeezing together the top parts ot the side walls of the corrugations into parallel plan at substantially right angles to the plane oi' the sheet or strip and at the saine time raising the central longitudinal part ot the sheet or strip with the corrugations, Whereby the top parts ot the corrugations are raised and reduced in thickness, and at the same time an inverted longitudinal gutter is formed; holding down the ends ot the ridges Where they have been slit away from the loops and simultaneously pinching the tops of them together; then pressing down the tops ot the eorrugations into substatially the plane of the tops of the loops, and pressing down the lower parts ot the side Walls ot the ridges into the plane ot the bottom of the gutter, and pressing down the side Walls of the ridges adjacent the pinched together ends into the original plane ott the sheet to torni sealing margins along both edges.

ll. The method otl producing a radiator core section consisting` in forming a tube ot similar halves with a straight v'ater passageway trom end to end While forming the same from a strip to provide a central chain nel portion and lat-eral corrugations with integral laterally deflected loops on an. edge ol'V the channel portion. separating the loops therefrom by a slit With the lateral corrugations all lying in register with the loops and taking up the necessary linear surplus ot metalto compensate tor the metal required for the laterally deflected loops.

12. In the method ot forming a radiator tube from a strip of sheet metal, the com bination of the following operation: slitting the metal along the edge ot the strip7 'form ing the longitudinal central portion oi thtl strip into a channel, shrinking the shee longitudinally to form loops Vtrom said slit portions alongl the edges and water legs or corrugations along the lateral sides ol the channel and joining tivo halt tubes to make a tube.

13. In the method ot constructing radiator core section, the combination ot the :tollowing operations, slitting the blank adjacent each edge at regular intervals, longitudinally tolding the blank to torni an intermediate trough and transversely Folding the outer portions ot' the blank along each of the slits to 'torm depending loops of sheet metal extending laterally :trom the plane ot the original sheet and below the level ot the corrugated trough bottom.

14. In the method ot forming a radiator core section, the combination ot the following operations; slitting the blank adjacent each edge, longitudinally folding the blanks between the rows to form a trough having an irregular' bottom and side walls, folding the portions outlying the slits toform outlying` depending loops of sheet metal at each slit, taking up the excess of metal in the intermediate portion lying between the slit` and the trough edges by forming closed transverse loops, then placing the..two like formed units face to face to form a flattened tube, each trough forming a half thereof, and sealing the tube on either side by soldering the contacting` metal surfaces of adjacent halves together.

if). ln the method of making a radiator core wall, slitting a sheet of thin metal along each edge, then folding the blank to form an intervening longitudinal trough between the slits, the said trough being crimped transversely, folding the outer portionsl of the blank outside each of the slits to create loops of sheet metal extending beyond the corrugated trough bottom.

1G. rlhe method of forming a radiator core section which comprises, slitting a blank along its edges, offsetting the central part of the sheet between the rows to form a trough with outer flanges or joining` margins, folding the outer edges of the strip outlying the slits to form depending loops of sheet metal at each slit, taking up the excess of metal between the slits and the trough edges by forming closed transverse pockets, then placing the two like formed units face to face to foi-m a flattened tube of which each trough forms a half, and then sealing the tube by soldering the contacting metal surfaces of the respective units together.

l?. ln the method of making a radiator core .section the following steps, slitting a sheet of metal at intervals along its edges, longitudinally forming the blank to form an inverted trough, crimping the said trough transversely of its length to form closed pockets along the sides of the trough and to create laterally extending open loops of sheet metal along the edges and soldering two halves together to form a tube.

18. The method of manufacturing a radiator core section consisting in first subjecting each of a pair of metal sheets to the following operations; folding each sheet to forni a central longitudinal trough in a single plane having a transversely corrugated bottom and having side walls, and sealingl margins, transversely folding the edges of the sealing margins to form closed poel*- ets of said corrugations, severing and depressing integral loops from the edge of the metal and transverse corrugations, then placing both formed sheets face to face to cause the sealing` margins to be brought into Contact and then soldering said sealing margins.

i9. rlhe lmethod of manufacturing sheet metal radiator core section involving the following steps; folding each of a paixl of like metal sheets to form longitudinal ei;- tending troughs from each sheet, transverse ly corrugating the trough bottoms, slitting and laterally deflecting integral portions from the edge of the metal sheets in a regular pattern, placing the so formed sheets face to face with the edges thereof in contact and joining saidl edges by soldering.

20. The method of forming radiator tubes from strips of sheetmetal comprising the following steps, cutting and forming free loops in a regular cellular pattern from the edges of the sheet or strip, forming a longitudinal gutter with flat joining margins and with transversely extending closetL end aockets or water legs to take up the same amount of metal as is employed for said loops, and joining complementary gutters along said joining margins to form tubes.

2l. The method of forming a sheet metal radiator tube which comprises forming slits along an edge of a sheet metal strip, offset-- ting the tted portions adjacent the edge to form loops and simultaneously forming lateral corrugations in the body of the metal adjacent the loops so that the metal may be substantially equally foreshortened across the full width of the metal strip.

22. rl"he method of forming a radiator tube half from a strip of sheet metal which comprises the following steps, deiiecting laterally integral parts of the sheet and slitting the same to form free loops along the outer n'iargins and to form closed pockets or water legs along the intermediate central part, and equally foreshortening the strip across the full width thereof by said loops and said pockets.

23. The method of forming a radiator tube halt' from a strip of sheet metal which coniprises the following steil e detiectirfg laterally integral parts of tl reet and sl tting the same to form free loo] Iiloag 'the outer margins and to form closev pockets or water legs along the intermediate central pt t, and equally foreshortening the strip across the full width thereof by said loops and said pockets, and forming a longitudinal median depression or gutter with fiat joining margins at each side thereof.

'lfhe method of forn'iing sheet metal tubes out of sheet inetal strips which comprises forniing slits adjacent one edge of the strip, bending the slitted portion laterally to form an ornamental loop or lin for the front of the tube and corrugating the body of metal transversely to take up the surplus metal which is caused by the lateral. bending of the slitted portion.

rlhe method of forming sheet metal tub-es ont of sheet metal strips which comu prises forming slits adjacent one edge of lll) the strip. bending the slitt-ed portion latorallyY to torni an ornamental loop or tin for the iront ot the tube and corrugating the lio-dv c irtal trl1 srersely to taire up the i wlnxh causer by the lateral d portion and closing 1rufations to form water -v s along the sides ot the tube. ofi' v.nnngfa radiator tube following steps, slitting a g one edge ot the same7 'told in the body oi' the 'e to provide a surplus and bending said Slitted torni an ornamental loop.

the metal along i' to torni loops tepral remainder oi" the i nter lowfitudinally ot the ng the strip laterally across -d adjacent the slitted portion 25 'ansverseiy ot the gutter por- .iirq the slitted portions along laterallv to forni ornainental ln the method olI itorniing a radiator' rom a strip of sheet metal the f0llowtops. namely, slitting the strip of meta al nt one edge thereof, then longitudinally toreshortening the strip by bending the slitted portion laterally and by torming 5 a cre se transversely of the body of the strip, Yforming a gutter lengthwise the strip o'i metal. `"iid gutter having `ioining inargins alongv Ls edges, then collapsing the edges o' rthe transverse creases to close the sa secl'ely t .t the edges to form pockets Ol, )5. rem od oit rollowing i forming a radiator etc; s. namely. slitting a et metal along one edge ot' the n loops or tins. oiisetting said lirerallv to toi-.xn ornamental to regular pattern. and i taneousiv toreshortening the sheet bethe loo/ps to t'orm closed water legs ou. lu ,he method ot forming a 'radiator lowing steps, namely, slitting a .et metal along one edge oi" the "orin loops or fins, o'tlisetting said i .,trin ot saine to loops or linu latera ly to term ornamental liiuires uccoroing to a regular pattern, and simultaneously Vtoreshortening the sheet betheI loops to form closed water legs and torn'iing a gutter or longii pression in the central part or' the sheet. sait gutter ha 'ing joining margins. 1. In the method of forming a radiator e. coniprising the following steps, namely, c a strip oi sheet metal along one edge the saine to torni loo-ps or fins, oli'setting said loops or fins laterally to form ornamcn tal figures. and simultaneously roreS-hortenthe ends or a loop to forming other and he i. ping the lateral loe solder to close 'the s along p 3Q. lihe method of forming automobile radiator cores consisting in forming tubes by pressing similar halves into a central channelV portion to form a straight water passage troni end to end, Jforming the same with lateral corrugationshaving closed ends by pressing the metal 'together in spaced rela-- tion to the edges ot the halves, slitting the halvesa detlecting loops laterally beyond said channel portion on each edge or' said portion and separating the same therefrom by a slit so as to dispose the lateral corrugations in register with the loops at the same side, and causing the loops and corrngations to take up the samc'length of metal whereby the corrugations will comprise the necessary linear surplus ot metal to compensate for the metal required tor the laterally dellected loops.

rlhe method of manufacturing a radiator core section consisting in lirst sub jecting each ot a pair ot independent metal sheets to the following operations; folding each sheet to form a longitudinal trough in a single plane having a transversely corrugated bottom and having side walls, and sealing margins, transversely folding the edges ot the sealing margins to lorni closed pockets ot said corrugationsj severing the edges of the sheets at spaced points, depressing integral loops from the severed edges oi the metal7 then placing both formed sheets face to face with their troughs toward each other, to cause the sealing margi to be brought into contact and then joining said sealing margins.

34. The method ol forming a radiator tube from a strip of sheet met-al which comprises the following steps9 slitting and vdctlecting laterally integral parts or the sheet Ytorni tree loops along the margins, forming closed pocket-s or water legs along the il'iterinediate central part between the slits, and equally 'tore-shortening the strip across the tull width thereof by said loops and said pockets.

85. rlhe herein described process 'lor iorming a radiator halt tube ont ot' a strip ot' sheet metal comprising corrngating said strip, slitting alternate ridges to tree the ccntral part of the transverse rid res therebetween from the marginal portions, and contracting the strip inwardly ot said marginal portions.

36. The method of forming a radiator tube from a strip of sheet metal including corrugating said strip with transverse ridges,

loo

slitting the strip longitudinally adjacent alternate ridges to ee the marginal portions trom the central portionsto *form loops, and shrinliiiigthe ends ot the corrugations adj acent the loops to close the ends ot' adjacent ridges.

237. The method ot forming a radiator tube trom a strip ot `sheet metal including Vcorriiigating said strip with transverseridges, slitting the strip longitudinally adjacent alternate ridges to tree the marginal portions trom the central portions to torni loops and shrinking the metal of the strip between alternate ridges where slit to provide substantially flat marginal portions substantially in the plane ot the alternate loops, and joining i'omplementary halt tubes thus formed along said marginal portions and at the loops.

38. rll`he method of forming a radiator tube trom a strip of sheet metal including corrugating said strip with transverse ridges, slitting the strip longitudinally adjacent alternate ridges to tree the marginal portions trom the central portions to form loops and gathering the ends otl alternate ridges in line with alternate loops to take up linear surplus ot metal and provide narrow longitudinal flat portions at the ends ot the ridges inwardly oit' the slits and loops for contact between and joining complementary halt' tubes.

39. The herein described method ot making radiator cores consisting in corrugating a strip ot sheet metal transversely to provide equally and .oppositely pitched transverse ridges, slitting the strip longitudinally near the margins thereo't in line with alternate ridges to form free loops with flat, narrow straight portions between the loops and ridges, and joining complementary sections thus formed at the narrow portions and tops ot the ridges ot said loops.

40. The herein descri-bed method of making radiator cores consisting in corrugating a strip ot sheet metal transversely to provide equally and oppositely pitched transverse ridges, slitting` the strip longitudinally near the margins thereof in line with alternate ridges to form 'free loops with flat, narrow straight portions between the loops and ridges, and contracting the strip opposite said alternate loops and at the ends ot aligned ridges to provide substantially flat portions at the back, forming soldering connections together with loops between complementary sections thus produced.

4l. The method of forming a radiator tube from a strip of sheet metal which comprises the following steps, slitting and deiieeting laterally integral parts of the sheet to form loops along the margins and to form closed pockets along the intermediate central part, and shrinking lengthwise portionsL between the pockets and loops.

42. The method of forming a radiator tube from a strip of sheet metal which com- 4prises the tollowingsteps,slitting the sheet u at spaced points and detlecting laterally integral. parts vot the sheet thus toi-ined to .torni loops along the margins and to torni transltween the pockets and loops, to provide tlat mai iisitcr connection with complementary Vmargins ot anotherstii'ip and close the ends ot the pockets.

48. The herein described process tor torming a radiator halt tube out of a strip otl sheet metal comprising slitting alternate ridges formed by corrugating the strip to free the central part of the transverse ridges therebetween from the marginal portion and shrinking joint margins between the ends of the transverse ridges and the marginal portions to close the ends ot' the ridges and taire up linear surplusage of the metal.

44. In the method ot forming a radiator tube from a strip of sheet metal, the combination of the following operations; slitting the metal along the edge ot the strip at spaced points, forming the longitudinal central portion of the strip into transverse ridges and marginal loops outside oi' the slits, and shrinking portions ot the sheet longitudinally to form jointing margins throughout the length of the strip inside the slits.

45. The method of forming a radiator tube comprising the following steps, slitting a strip of metal along one edge of the same, forming a transverse told in the body ot the metal adjacent the slit to provide a surplus of metal in a longitudinal direction along the slitted portion, gathering said surplus metal, and bending said slitted portion laterally to lorm 'an ornamental loop.

46. The method of forming a radiator tube comprising the 'following steps, slitting a strip of metal along its edges, forming trans verse corrugations therein and shaping the portions outwardly ot the slit to form loops, and shrinking narrow marginal portions between the corrugations and loops to'provide portions by which complementary strips so formed may be solderedtogether in conjunction with the loop ridges.

47. The herein described method oi making radiator core tubes comprising the tollowing steps; slitting the edges ot the sheet to tree portions for forming integral loops, shrinking the sheet endwise to form the slit parts into loops and to forni the central parts into corrugations taking up the same length of material as the loops, and gathering the edges ot the material into dat joining margins.

48. The method orp producing a radiator consisting in forming a tube of similar halves with a straight water passageway from end to end while forming the same from a strip to provide a central channel l0 from the builtup tubes.

49. The novel method of forming a tube section from a strip of sheet material oonsisting in slitting the metal7 forming chenn'els therein, compressing the channel ends and depressing the marginal portions of the Strip adjacent the channel ends to form lree loops at the ends of the channels.

In Witness whereof7 I hereunto subscribe my name this 6th day of November, 1922. FRED M. QPITZ. 

